serial: mxs-auart: disable clks of Alphascale ASM9260

In case of Alphascale ASM9260 probe() enables s->clk and s->clk_ahb
via mxs_get_clks(), but there is no disable of the clocks.
The patch adds it to error paths and to mxs_auart_remove().

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Fixes: 254da0d ("serial: mxs-auart: add Alphascale ASM9260 support")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/mxs-auart.c

@@ -1678,8 +1678,10 @@ static int mxs_auart_probe(struct platform_device *pdev)
 		return ret;
 
 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!r)
-		return -ENXIO;
+	if (!r) {
+		ret = -ENXIO;
+		goto out_disable_clks;
+	}
 
 	s->port.mapbase = r->start;
 	s->port.membase = ioremap(r->start, resource_size(r));
@@ -1694,37 +1696,39 @@ static int mxs_auart_probe(struct platform_device *pdev)
 	s->mctrl_prev = 0;
 
 	irq = platform_get_irq(pdev, 0);
-	if (irq < 0)
-		return irq;
+	if (irq < 0) {
+		ret = irq;
+		goto out_disable_clks;
+	}
 
 	s->port.irq = irq;
 	ret = devm_request_irq(&pdev->dev, irq, mxs_auart_irq_handle, 0,
 			       dev_name(&pdev->dev), s);
 	if (ret)
-		return ret;
+		goto out_disable_clks;
 
 	platform_set_drvdata(pdev, s);
 
 	ret = mxs_auart_init_gpios(s, &pdev->dev);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to initialize GPIOs.\n");
-		return ret;
+		goto out_disable_clks;
 	}
 
 	/*
 	 * Get the GPIO lines IRQ
 	 */
 	ret = mxs_auart_request_gpio_irq(s);
 	if (ret)
-		return ret;
+		goto out_disable_clks;
 
 	auart_port[s->port.line] = s;
 
 	mxs_auart_reset_deassert(s);
 
 	ret = uart_add_one_port(&auart_driver, &s->port);
 	if (ret)
-		goto out_disable_clks_free_qpio_irq;
+		goto out_free_qpio_irq;
 
 	/* ASM9260 don't have version reg */
 	if (is_asm9260_auart(s)) {
@@ -1738,13 +1742,15 @@ static int mxs_auart_probe(struct platform_device *pdev)
 
 	return 0;
 
-out_disable_clks_free_qpio_irq:
-	if (s->clk)
-		clk_disable_unprepare(s->clk_ahb);
-	if (s->clk_ahb)
-		clk_disable_unprepare(s->clk_ahb);
+out_free_qpio_irq:
 	mxs_auart_free_gpio_irq(s);
 	auart_port[pdev->id] = NULL;
+
+out_disable_clks:
+	if (is_asm9260_auart(s)) {
+		clk_disable_unprepare(s->clk);
+		clk_disable_unprepare(s->clk_ahb);
+	}
 	return ret;
 }
 
@@ -1755,6 +1761,10 @@ static int mxs_auart_remove(struct platform_device *pdev)
 	uart_remove_one_port(&auart_driver, &s->port);
 	auart_port[pdev->id] = NULL;
 	mxs_auart_free_gpio_irq(s);
+	if (is_asm9260_auart(s)) {
+		clk_disable_unprepare(s->clk);
+		clk_disable_unprepare(s->clk_ahb);
+	}
 
 	return 0;
 }